Long-term use won't cut extract's erectile effects

NEW YORK (Reuters Health) - A nutritional supplement that helps men achieve erections doesn't lose its effectiveness when used for several months, new research funded by the supplement's maker shows.

"The benefits persist as long as men continue to use it," said Dr. Frank Schonlau, a co-author of the study, who works for the London-based supplement maker Horphag Research UK.

The supplement, Prelox, contains pine bark extract and the amino acid L-arginine aspartate. Studies lasting up to six weeks have shown it improves erectile function in men with mild to moderate erectile problems. The researchers conducted the current study to determine if it would continue to help men who took it for up to six months. There had been concerns, Schonlau noted, that men might become less responsive to the supplement over time.

The researchers assigned 124 men 30 to 50 years old to take two tablets of Prelox twice daily, or an inactive placebo, for six months. Most of the men's erectile problems were likely related to mild, untreated hypertension (high blood pressure), Schonlau said.

Men in both groups had moderately high blood pressure and "borderline high" total cholesterol levels. None had severe hypertension or diabetes. They were instructed to lose weight, cut down on their salt intake, and exercise, in addition to taking the supplement or placebo pills.

Men in both groups scored an average of 15 on a 30-point standardized score measuring erectile function, corresponding to mild to moderate erectile dysfunction. At three months, average scores were 25 for the Prelox group (a 25-30 point score signifies no dysfunction) and 19 in the placebo group (19-24 indicates mild dysfunction); at six months, average scores were 27 for the Prelox group and 19 for the placebo group.

The men in the Prelox group also showed significantly greater improvements in other aspects of sexual function compared to men in the placebo group, including orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction.

Because a man's blood vessels need to be in good working order for him to achieve erection, loss of erectile function is closely tied to heart health, Schonlau noted. "In essence, everyone who has any kind of cardiovascular problem does already or will in the future develop erectile function problems," he said.

Prelox works by restoring the ability of the blood vessels to produce nitric oxide, which triggers blood vessel dilation, he added; Viagra works through a similar mechanism, but later in the process, by amplifying nitric oxide's effects.